Context and consequences of cardiac arrest in acute coronary syndrome: the impact of resuscitation setting and PCI strategy on survival and neurological outcomes

Background Cardiac arrest in acute coronary syndrome (ACS) carries high mortality and neurological morbidity. The optimal approach - immediate rescue percutaneous coronary intervention (PCI) or conservative care - remains uncertain, with outcomes influenced by resuscitation location and status at arrival to the catheterisation laboratory. Purpose To determine how resuscitation context (location and status at arrival) influences in-hospital survival and neurological outcomes in ACS patients undergoing catheterisation, and to evaluate the role of rescue PCI in refractory arrest. Methods Two retrospective cohorts were analysed from 14,839 ACS patients undergoing catheterization (2014–2024). The first included 125 patients resuscitated before or during the procedure, classified as already resuscitated (RES) or in refractory arrest requiring automatic resuscitation devices (ARD). The second comprised 151 patients who experienced cardiac arrest before or during catheterization, grouped by resuscitation location: out-of-hospital, in-hospital, or in-laboratory. Across both analyses, primary outcomes were in-hospital mortality and post-resuscitation neurological status. Retrospective analysis was conducted using IBM SPSS software. Results In the first cohort (n=125), in-hospital mortality was 39.6% in patients resuscitated before catheterisation (RES; n=106) versus 84.2% in those with refractory cardiac arrest requiring an automatic resuscitation device (ARD; n=19); p<0.001. Only three ARD patients survived, of which two remained in a coma due to severe post-hypoxic encephalopathy. Among RES survivors, 60.3% had favourable neurological outcomes, 20.6% were discharged in a coma, and 19.1% had mild to moderate neurological deficits (p = 0.19). In the second cohort (n = 151), stratified by resuscitation location, 79 patients (52.3%) experienced out-of-hospital arrest, 46 (30.5%) were resuscitated in-hospital, and 26 (17.2%) suffered arrest within the catheterization laboratory. In-hospital mortality was 39.2% in the out-of-hospital group, compared to 58.7% in the in-hospital group (p = 0.028). The in-laboratory group had the highest mortality rate at 76.9% (p < 0.001). Neurological outcomes varied across groups: 53.8% of out-of-hospital and 70.0% of in-hospital patients had good recovery, while 23.1% and 20.0%, respectively, were discharged in a coma (p = 0.44). Notably, all surviving in-laboratory patients had no encephalopathy. Conclusion In ACS with cardiac arrest, outcomes are driven by resuscitation context. Refractory arrest requiring automatic resuscitation devices during PCI carried near-universal mortality and severe neurological injury, indicating limited benefit of rescue PCI. In-hospital arrests had higher mortality but slightly better neurological recovery than out-of-hospital cases. Cath-lab activation should be selective, prioritising patients with achievable return of spontaneous circulation and recovery potential.